Soil stiffness non-linearity in the settlement analysis of foundations.

The purposes of this thesis are: -The study of the non-linear behaviour of soil interacting with a foundation, investigating the main influence factors. -The study of the link between the stiffness values deduced in laboratoryand in-field. -The analysis of methods for the evaluation of settlements of foundations with a special regard to sand. -The proposal of simple procedures in order to obtain stiffness values to be adopted in elastic frameworks so as to forecast displacements of foundations, taking non-linearity into account. The geotechnical structures here considered are shallow and deep foundations. Although these two types of examined foundations behave in a different way, the evaluation of their settlements can be faced similarly, and a special prominence is given to this correspondence